The Experts below are selected from a list of 52566 Experts worldwide ranked by ideXlab platform
Yuan Zhang - One of the best experts on this subject based on the ideXlab platform.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8,650 ng g for ΣPAHs and 83.3 to 7,220 ng g for ΣPAHs, with mean values of 2420 and 1,970 ng g, respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP) concentrations ranged from 48.9-2,580 ng g for ΣPAHs, 7.02-869 ng g for ΣPAHs and 35.7-1,990 ng g for ΣDBPs. The BaP concentrations of ΣDBPs made up 72% of ΣPAHs. Nearly half of the soil samples showed concentrations above the safe BaP value of 600 ng g. Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:Abstract A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8650 ng g − 1 for Σ 26 PAHs and 83.3 to 7220 ng g − 1 for Σ 16 PAHs, with mean values of 2420 and 1970 ng g − 1 , respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP eq ) concentrations ranged from 48.9–2580 ng g − 1 for Σ 24 PAHs, 7.02–869 ng g − 1 for Σ 16 PAHs and 35.7–1990 ng g − 1 for Σ 4 DBPs. The BaP eq concentrations of Σ 4 DBPs made up 72% of Σ 24 PAHs. Nearly half of the soil samples showed concentrations above the safe BaP eq value of 600 ng g − 1 . Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
Xuetong Wang - One of the best experts on this subject based on the ideXlab platform.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8,650 ng g for ΣPAHs and 83.3 to 7,220 ng g for ΣPAHs, with mean values of 2420 and 1,970 ng g, respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP) concentrations ranged from 48.9-2,580 ng g for ΣPAHs, 7.02-869 ng g for ΣPAHs and 35.7-1,990 ng g for ΣDBPs. The BaP concentrations of ΣDBPs made up 72% of ΣPAHs. Nearly half of the soil samples showed concentrations above the safe BaP value of 600 ng g. Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:Abstract A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8650 ng g − 1 for Σ 26 PAHs and 83.3 to 7220 ng g − 1 for Σ 16 PAHs, with mean values of 2420 and 1970 ng g − 1 , respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP eq ) concentrations ranged from 48.9–2580 ng g − 1 for Σ 24 PAHs, 7.02–869 ng g − 1 for Σ 16 PAHs and 35.7–1990 ng g − 1 for Σ 4 DBPs. The BaP eq concentrations of Σ 4 DBPs made up 72% of Σ 24 PAHs. Nearly half of the soil samples showed concentrations above the safe BaP eq value of 600 ng g − 1 . Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
Yi Miao - One of the best experts on this subject based on the ideXlab platform.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8,650 ng g for ΣPAHs and 83.3 to 7,220 ng g for ΣPAHs, with mean values of 2420 and 1,970 ng g, respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP) concentrations ranged from 48.9-2,580 ng g for ΣPAHs, 7.02-869 ng g for ΣPAHs and 35.7-1,990 ng g for ΣDBPs. The BaP concentrations of ΣDBPs made up 72% of ΣPAHs. Nearly half of the soil samples showed concentrations above the safe BaP value of 600 ng g. Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
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polycyclic aromatic hydrocarbons pahs in urban soils of the megacity shanghai occurrence source apportionment and potential human health risk
Science of The Total Environment, 2013Co-Authors: Xuetong Wang, Yi Miao, Yuan ZhangAbstract:Abstract A comprehensive investigation was conducted to the urban soil in the megacity Shanghai in order to assess the levels of PAHs and potential risks to human health, to identify and quantitatively assess source contributions to the soil PAHs. A total of 57 soil samples collected in main urban areas of Shanghai, China were analyzed for 26 PAHs including highly carcinogenic dibenzopyrene isomers. The total concentrations ranged from 133 to 8650 ng g − 1 for Σ 26 PAHs and 83.3 to 7220 ng g − 1 for Σ 16 PAHs, with mean values of 2420 and 1970 ng g − 1 , respectively. DBalP and DBaeP may serve as markers for Diesel vehicle emission, while DBahP is a probable marker of coke tar as distinct from Diesel Emissions. Six sources in Shanghai urban area were identified by PMF model; their relative contributions to the total soil PAH burden were 6% for petrogenic sources, 21% for coal combustion, 13% for biomass burning, 16% for creosote, 23% for coke tar related sources and 21% for vehicular Emissions, respectively. The benzo[a]pyrene equivalent (BaP eq ) concentrations ranged from 48.9–2580 ng g − 1 for Σ 24 PAHs, 7.02–869 ng g − 1 for Σ 16 PAHs and 35.7–1990 ng g − 1 for Σ 4 DBPs. The BaP eq concentrations of Σ 4 DBPs made up 72% of Σ 24 PAHs. Nearly half of the soil samples showed concentrations above the safe BaP eq value of 600 ng g − 1 . Exposure to these soils through direct contact probably poses a significant risk to human health from carcinogenic effects of soil PAHs. The index of additive cancer risk (IACR) values in almost one third of urban soil samples were more than the safe value of 1.0, indicating these urban soil PAHs in the study area may pose a potential threat to potable groundwater water quality from leaching of carcinogenic PAH mixtures from soil.
Philip K Hopke - One of the best experts on this subject based on the ideXlab platform.
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source apportionment of airborne particulate matter using inorganic and organic species as tracers
Atmospheric Environment, 2012Co-Authors: Yungang Wang, Philip K Hopke, Xiaoyan Xia, Oliver V Rattigan, David Chalupa, Mark J UtellAbstract:Abstract Source apportionment is typically performed on chemical composition data derived from particulate matter (PM) samples. However, many common sources no longer emit significant amounts of characteristic trace elements requiring the use of more comprehensive chemical characterization in order to fully resolve the PM sources. Positive matrix factorization (EPA PMF, version 4.1) was used to analyze 24-hr integrated molecular marker (MM), secondary inorganic ions, trace elements, carbonaceous species and light absorption data to investigate sources of PM2.5 in Rochester, New York between October 2009 and October 2010 to explore the role of specific MMs. An eight-factor solution was found for which the factors were identified as isoprene secondary organic aerosol (SOA), airborne soil, other SOA, Diesel Emissions, secondary sulfate, wood combustion, gasoline vehicle, and secondary nitrate contributing 6.9%, 12.8%, 3.7%, 7.8%, 45.5%, 9.1%, 7.9%, and 6.3% to the average PM2.5 concentration, respectively Concentrations of pentacosane, hexacosane, heptacosane, and octacosane in the gasoline vehicles factor were larger compared to Diesel Emissions. Aethalometer Delta-C was strongly associated with wood combustion. The compounds, n-heptacosanoic acid and n-octacosanoic acid, occasionally used in the past as tracers for road dust, were found to largely associate with SOA in this study. In comparison with a standard PMF analyses without MM, inclusion of them was necessary to resolve SOA and wood combustion factors in urban areas.
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source apportionment of pm 2 5 in seoul korea
Atmospheric Chemistry and Physics, 2009Co-Authors: J B Heo, Philip K HopkeAbstract:Abstract. PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using positive matrix factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 source categories were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major contributors of PM2.5 were secondary nitrate (20.9%), secondary sulfate (20.5%), gasoline-fueled vehicles (17.2%), and biomass burning (12.1%), with lesser contributions from Diesel Emissions (8.1%), soil (7.4%), industry (6.7%), road salt and two-stroke vehicles (5.1%), and aged sea salt (2.2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional probability function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and Diesel), industry, and road salt. Potential source contribution function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.
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improving source identification of atlanta aerosol using temperature resolved carbon fractions in positive matrix factorization
Atmospheric Environment, 2004Co-Authors: Philip K Hopke, Eric S EdgertonAbstract:Daily integrated PM2.5 (particulate matter ⩽2.5 μm in aerodynamic diameter) composition data including eight individual carbon fractions collected at the Jefferson Street monitoring site in Atlanta were analyzed with positive matrix factorization (PMF). Particulate carbon was analyzed using the thermal optical reflectance method that divides carbon into four organic carbon (OC), pyrolized organic carbon (OP), and three elemental carbon (EC) fractions. A total of 529 samples and 28 variables were measured between August 1998 and August 2000. PMF identified 11 sources in this study: sulfate-rich secondary aerosol I (50%), on-road Diesel Emissions (11%), nitrate-rich secondary aerosol (9%), wood smoke (7%), gasoline vehicle (6%), sulfate-rich secondary aerosol II (6%), metal processing (3%), airborne soil (3%), railroad traffic (3%), cement kiln/carbon-rich (2%), and bus maintenance facility/highway traffic (2%). Differences from previous studies using only the traditional OC and EC data (J. Air Waste Manag. Assoc. 53(2003a)731; Atmos Environ. (2003b)) include four traffic-related combustion sources (gasoline vehicle, on-road Diesel, railroad, and bus maintenance facility) containing carbon fractions whose abundances were different between the various sources. This study indicates that the temperature resolved fractional carbon data can be utilized to enhance source apportionment study, especially with respect to the separation of Diesel Emissions from gasoline vehicle sources. Conditional probability functions using surface wind data and identified source contributions aid the identifications of local point sources.
Octavio Armas - One of the best experts on this subject based on the ideXlab platform.
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effect of alternative fuels on exhaust Emissions during Diesel engine operation with matched combustion phasing
Fuel, 2010Co-Authors: Octavio Armas, Kuen Yehliu, Andre L BoehmanAbstract:Abstract The present work focuses on an experimental comparison of Diesel Emissions produced by three fuels: an ultra low sulfur Diesel fuel (BP15), a pure soybean methyl-ester bioDiesel fuel (B100), and a synthetic Fischer–Tropsch fuel (FT), practically free of sulfur and aromatic compounds, and produced in a gas-to-liquid process. The study was carried out using a 2.5 L direct injection common-rail turboDiesel engine operated at 2400 rpm and 64 N m torque (19% of maximum torque). The engine was tested with single and split (pilot and main) injections and without exhaust gas recirculation (EGR). The study has two objectives. The first objective is to investigate the impact of the start of injection (SOI) on performance and Emissions of each fuel. The second objective is to study the isolated impacts of the test fuels on pollutant Emissions by adjusting the injection parameters (SOI and fuel rail pressure) for each fuel, while producing practically the same combustion phasing. When the combustion phasing occurs similarly, this study has confirmed that the FT fuel can reduce all regulated Diesel Emissions under both single and split injection strategies. Finally, it has been confirmed that bioDiesel can reduce particle mean diameter in comparison with BP15. However, higher PM mass emission for B100 has been observed under the condition of matched combustion phasing. The increase of the PM mass emission is probably due to the unburned or partially burned hydrocarbon (HC) Emissions.
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Emissions from a Diesel bioethanol blend in an automotive Diesel engine
Fuel, 2008Co-Authors: Magin Lapuerta, Octavio Armas, Jose M HerrerosAbstract:Diesel Emissions have been measured from an automotive engine using anhydrous bioethanol blended with conventional Diesel, with 10% ethanol in volume and no additives. The resulting Emissions have been compared with those from pure Diesel. A stationary engine test bed, together with the instrumentation for measuring the most stringent regulated Emissions (nitric oxides, total hydrocarbons and particulate matter) and the particle size distributions, allowed to study the effect of this blend on the engine performance and Emissions under five different steady state operating conditions, selected from the transient cycle for light duty vehicles established in the European Emission Directive 70/220. Both the consideration of the thermochemical properties of the tested fuels and the computations of a chemical equilibrium model were helpful for the results analysis. These results proved that the use of this renewable component provides a significant reduction on particulate Emissions, with no substantial increase in other gaseous Emissions, which makes it helpful for contributing, on the one hand, to fulfil the European compromise of using more than 5.75% biofuels in 2010, and on the other hand, to stop the increase in particulate Emissions caused by transportation as a consequence of the unceasing Dieselization.
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Diesel Emissions from biofuels derived from spanish potential vegetable oils
Fuel, 2005Co-Authors: Magin Lapuerta, Octavio Armas, Rosario Ballesteros, Jesus FernandezAbstract:Methyl esters obtained from the most interesting Spanish oleaginous crops for energy use—sunflower and Cynara cardunculus—were both used as Diesel fuels, pure and in 25% blends with a commercial fuel which was also used pure. A stationary engine test bed, together with the instrumentation for chemical and morphological analysis, allowed to study the effect of these fuels on the engine Emissions, soluble organic fraction of the particulate matter, origin of adsorbed hydrocarbons, sulphate content, particle number per unit filter surface, and mean particle diameter. Both the consideration of the thermochemical properties of the tested fuels and the computations of a chemical equilibrium model were helpful for the results analysis. These results proved that the use of these vegetable esters provides a significant reduction on particulate Emissions, mainly due to reduced soot and sulphate formation. On the contrary, no increases in NOx Emissions nor reductions on mean particle size were found.